-8Xa squared b

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-5Xa fifth power b

To simplify the expression (-8Xa^2b) / (-5Xa^5b), you can divide the coefficients and subtract the exponents. Let me break down the steps for you:

Step 1: Divide the coefficients (-8 / -5) which gives you 8/5.

Step 2: Divide the variables with the same base (X and a) by subtracting their exponents. In this case, a^2 is divided by a^5, which gives you a^(2 - 5) = a^(-3).

Step 3: Divide the variable b by itself, which cancels out and leaves us with just 1.

Putting it all together, the simplified expression is (8/5)Xa^(-3) or (8X) / (5a^3).